Actuating mechanism and support for bomb bay doors



July 22, 1952 w. Buer-:AL ET AL 2,604,281

ACTUATING MECHANISM AND SUPPORT FOR BOMB BAY DOORS F11ed Aug. 11, 1948 7 sheets-sheet 1 fitto/mvg July 22, 1952 w. BUCHAL ET AL 2,604,281 ACTUATING MBCHANISM AND SUPPORT FOB BOMB BAY DooBs Filed Aug. 11. 194B '7 Sheets-Sheet 2 July 22, 1952 w. BUCHAL ETAL v 2,604,281

` ACTUATING MECHANISM AND SUPPORT FOR BOMB BAY DOORS Filed Aug. ll, 1948 7 Shen-zts-Shee'I 4 "'llll I W i! V// g y 1./ I f l .lilly 22; w52 w. BUCHAL AL ACTUATING MECHANISM AND SUPPORT FOR BOMB BAY DOORS '7 Sheets-Sheet. 55v

Rime@ 1mg. 11. 1948 VERNE/P BUCH/4L,

July 22, l1952@ w. BUCH'AL Eu- AL ACTUMBNG: MBBBANISM ANB SUPPORT' B0B BOMB BAY BooBs 7 Sheets-Sheet 6 Filed Aug. 11, 194@ July 22, 1952 w. BUCHAL ET AL 2,604,281

ACTUATING MECHANISM AND SUPPORT' FOR BOMB BAY DOORS Filed Aug. ll, 194B 7 Sheets-Sheet '7 NO Mv/4x, vd.

WEP/VEP @Ua/WL 7 COA/R170 H. CUO/(E,

bay of this invention consists of a floor that divides the fuselage so that the bomb bay is formed by the substantially 'ilat upper. transverse partition and the lower portion of the fuselage. A pair of long, single doors are pro-v vided, the pair beingsubstantially equal to the width of the fuselage so that aA maximum area of doorway will be available, opening downwardly. This type of bomb bay can accommodate a great variety of types of bomb load. It can accommodate several transverse, horizontal bomb racks. supporting bomb clusters, the number depending upon the size of the bombs, or it can supportz-a single large bomb substantially `filling tllebomb bay.

In Figures 1 and 1A of the draw-ings, then-outline of the fuselage is shown at I. Partition 2 in the fuselage forms the top of the bomb-bay and extends transversely of the fuselage. Structure 3 is a portion of the wing structure extending through the fuselage. Bomb bay 4 is included between bulkheads '5 and 6. Doors-1 operate in pairs and form a long, Vcontinuous closure for the opening in the bottom of the bombbay. The mechanism shown attached to bulkheads 5 and 6 and doors 1 will be described indetail subsequently.

In these figures,A a large. single vbomb Bis shown suspended in the bomb bay.;,.;The.; suspension consists of four articulated vlinkages I3 .to I6 secured to the frame work forming,;the top` of the bomb bay Vby brackets 9 I 0, I1I and I2.- Linkages I3, I4,-I5 and Ircomprise several members hinged togethenthe number of members is .denpendent'upon the circumference of the bomb-that they must encircle.V The ends oflinkages I3and I4 are secured to the bombshackle` I1. Y'Ihelends of linkagesI51and I6 have .terminal ttingsl and I9 that are'secured tothebcmb hooks -of'rthe bomb shackle: Adjustable ltbo'mb; chocksA 20 ze'ngage` the :periphery of .the bomband prevent swayingof the bombirrthe suspensionnunder side loads. Other bomb chocks2I securedatthe hinge point of the. articulated linkages I3 to I 6 hold the jbomb ,firmly in: the suspension. It should be ynoted` that linkages I,31and l5=arefor ward of V'the center of gravity ofi the bomb :and linkages I4 and I6 are aft of the center of-gravity of the bomb. To release the bomb, bomb shackle I1 is actuatedin the yusual manner releasing ttings I8 and I9, thereby disconnecting the Sus-` pending linkages soA thatthe bomb is free tofall from'thebomb bay. Y 1 g The loading of the bomb bay withclustersof bombs is shown inlligures 2, 2A and 5.- vThe h orizontal bomb'rack consists of a frame 22 from which are suspended bomb shackles I1.A The number and arrangement of such bomb shackles are dependent upon the size of the bombs and thenumber in the cluster. `Bombs ,231 are stackedonV an especially designed cart or carriage 24 softhat the bomb shackles I1 mayeasily and conveniently be attached `andther cluster; of bombs 'securedto bomb rack'22.l C art'"2 4,v;wi th the'bomb cluster ready for hoisting into the bomb bay, is moved into position under the bombA bay. Bomb rack 2 2 is elevated in to position in the bomb end of the bomb rack at 32.

bay by a pair of portable bomb hoists 25. hes bomb hoists consist of a gear box 26 driven by motor 21 controlled by push button 28. Chain 29 is fed through the gear box 26 and through pipe 3D. A tting 3| on the top of pipe 30 detachably secures the bomb hoist Vto the structure at the top of the bomb bay.v Chain 29 passes over a sprocket in tting 3| and is secured to the Latches 33 automatically engage rails 34 when hoisted to the top of the bomb bay which secures the horizontal bomb rack in place. The bomb hoists can then readily be disconnected from the bomb rack and the top of the bomb bay and removed for subsequent use. The bomb shackles can be operated in any predetermined sequence to release the bombs from the cluster separately or as a group.

The door actuating mechanism, shown in Figure 3, is the same on each end of the door adjacent bulkheads 5 and 6. Hydraulic cylinder 50 is vsecured at its upper end to the Stringer structure 5I supporting partition Y2. Doors] form a closure for the opening in the bottomf of the bomb bay andare moved by a quick-acting linkage assembly to the position shown at 1 wherein the doors are substantially `vertical andrcloseto the inside walls of the bombbay so that a maximum space will be afforded for the bomb load. The main pivot 52 is secured to the bulkhead and forms the support for the several linkages shown. Bell-crank linkage VVpivot 53 is also flxedwith respect to the bulkhead as ismaster link pivot 54; Master link 5'5 is pivoted at 51 at its lower end to a bracketn56 secured to Adoor "1. Link-58 is pivoted at one end 59 to bulkhead 5 and atthe other end 60 to the inner edge of the door. Linkage 58, therefore, determines the are of motion of the, inner edge yof the door. Linkage-Ifis securedto the other door and is pivoted at62 and 63 in a similarfashion. Members 5 5. ,66 and 61 form a bell-crank lever which-is pivoted at 58 to the door. vAri interconnecting lever 6 8 is pivoted to the bell-crank lever ail-10 and pivoted to thev upperend of masterlink 55 at 1 I. From the linkages described, it canybe seen that as the upper end of master link 55 is moved Vcounter-Y clockwise about xed pivot 54 the right 'hand door will move from a horizontal to a vertical position swinging on linkages 58.and ,'55 about pivot points- 5 9 and 54. As thenupper endg-of lmaster link 55 is moved, interconnecting link ,69 moves the bell-crank linkages 65, `B6 and 51, so

`that the left hand door is moved from a generally horizontal position to a vertical position swinging on the bell-crank linkage and linkage 6I pivoted about points 53 and 63.

A two-part linkage extend/s, between pivot points 52 and 1I. This linkageconsists of. por-f tions 12 and 13. Portions 12 and 13 are pivoted at their ends at points 52 and 1I andv intermediate the ends at pivot 14. It will be noted-that pivots 52,14and 1I are in a'straight line. A spring 15 acts'between an abutment 16 onmember 12 and :an abutment 11 on member, ,13, tending'to keep pivots 52, 1 4 and 1I in the 'same straight line. End portion 18 of leverg13 abuts against the side of lever 12- when the. three pivot points mentioned above are aligned;: Strut 19; fromA hydraulic cylinder 5I) is pivoted on mem-.- ber 13 at 80. It will be noted that -upon motion. of strut 19, pivot point is out of -line withll and exerts a force to overcome spring 15 ,andcause pivot point 14 to go out of alignment with pivots 52 and 1I and move the upper endzof master link 55 to actuate the linkage mechanism:

to open lt'h'e. doors. Spring :1.5 can :normally exertlsuflicient force to. cause. ithe compound linkl 12413 'toma'intainits three fpivo't points in alignment andrthe'refore, forms. an adequate lock for the door actuatingmechanismthat-.can onlybe unlocked when cylinder 50 exertsa force'to overcome'lthe spring. When the doors aremoved'to the open'zrpos'ition, compoundlinkage '|2-13 iis moved'toa substantially vertical position with themcylinderf-s'trut extended and the spring 75 again'alignsf'the'three pivot points 52, 'I4 and of the compoundlinkage 'l2-13 to form a lock for the door actuating linkage mechanism. In the open position, linkage 12-13 can only be broken to unlock by the retraction of strut 79 into cylinder 50.

Because of the extreme length of the bomb bay door, it isneoessary to have a -center support v151.02% will support the door in the open and closed positions but that will not interfere with the maximum size bomb that may be ,carried in the bomb bay. vSuch asupport is `shown in `lligure 4. Bracket |00 is secured to the top of the bomb bay and depends therefrom.l 'It is located suiiiciently to the side of the centerline -of the bomb bay so that itwill not interefere with vthe maximum size bomb 8 lthat may be carried therein. Door- -'|*has a bracket at mid length |0| secured thereto. A master link |02 is pivoted to bracket |0| and to the ends of linkages |03 and |04 which are in turn secured to bracket |00. Linkages |02, |03 and |04 and bracket |00 form a parallelogram designed to give the proper motion of the door from the closed to the open position that will also cause minimum interference with the load area of the bomb bay.

Lights 35 are mounted in doors 'l so that the upper portion of the bomb bay Where connections for the bomb shackles, etc., must be made are illuminated from within the airplane. This greatly facilitates loading the bomb bay with the right amount of light Where it is needed.

It is to be understood that certain changes, alterations, modifications and substitutions can be made without departing from the spirit and scope of the appended claims.

We claim as our invention:

l. An airplane fuselage having a bomb bay formed therein, a pair of doors forming a faired closure for said bomb bay extending longitudinally of said bomb bay. .both longitudinal edges of each said doors being free to move with respect to the bomb bay from the closed to the open position, linkage means secured at spaced points along said bomb bay and said doors to move said doors from a generally horizontal, closed position, with their inner edges abutting, to a generally vertical position Within said bomb bay contiguous the inner Walls thereof to afford a maximum of clear bomb dropping space, with a minimum of aerodynamic drag on a bomb run, said linkage means comprising a pair of rigid links associated with each door and pivoted directly to said fuselage and to said door at spaced points adjacent the end thereof, the pivots for one of said links being so located that the inner edge of said door is caused to initially swing downwardly so as to rock said door about the pivotal connection of the other link to the door whereby to swing the outer edge of the door upwardly and inwardly of said fuselage to clear the wall thereof.

2. An airplane fuselage having a bomb bay formed therein, a pair of doors forming a faired 6'.. closure therefor extending longitudinallyxofsaid bomb bay, both longitudinal edges of 1 each saiddoors being free tomove 1 Withurespect to the bomb-bay :from the .closed l.to-"the open position, linkage :means securedv .at spaced jpoints along said bomb bayA and said doors ftomove -said doors from a lgenerally horizontal abutting closed position, tofa .generally vertical position within A said bomb bayy contiguous the inner walls thereof vto affordza maximum of. clear bomb. dropping space, With a minimum of -areodynamic drag Aon a .bomb -run, said linkage means `comprising fa master link extending 'from a bracketon one of s'aidsdoors vtoene ,end .of a two-part looking lever, the 4other 'endz of 4said .leverf being `secured to the bulkhead on thecenterline-of. thefuselage," said .master lever .being pivoted,intermediate'said ends, 4ailinkage `secured-Lto each door on onegend adjacent thel Aabuttinfgedges of said doors-the other ends of,-.sai'd linkages being secured to said bulkheadsfto guide -said edgeof said door' in 4an arcuate path, a bell-crank lever Yhaving Athe outer endvof one' arm-secured to the second door,` the intermediate .pivot r.point of which is secured Ato the bulkhead, an. interconnecting link interposed between-thelupper end pivotof the master lever and-:the other arm-of the bellecrank,-springmeans to maintain said two-part linkage aligned to maintain the upper end of the master lever a fixed distance from the pivotal support of the other end thereof on the bulkhead, for both open and closed positions of the doors to hold said positions of the doors independent of the actuating mechanism, a hydraulic cylinder having a strut secured to one end of the two-part link adjacent said master control lever pivot, said pivotal connection of the hydraulic strut being off-set from the pivotal connection of the upper end of said master control lever on said two-part link to afford a torque in said two-part link to break and unlock said link so that the strut of the hydraulic cylinder may move the master con# trol lever and the bell-crank lever through the interconnecting link to move the doors from the closed to the open position.

3. `An airplane fuselage having a bomb bay formed therein, a pair of doors forming a faired closure therefor extending longitudinally of said bomb bay, both longitudinal edges of each said doors being free to move with respect to the bomb bay from the closed to the open position, linkage means secured at spaced points along said bomb bay and said doors to move said doors from a generally horizontal abutting closed position, to a generally vertical position within said bomb bay contiguous the inner walls thereof to afford a maximum of clear bomb dropping space, with a minimum of aerodynamic drag on a bomb run, said linkage means comprising power-actuated linkages at the ends of said doors adjacent the bulkhead and a door center supporting linkage consisting of members depending from the top of said bomb bay, one over each door spaced laterally from the center of the bomb bay to clear the largest bomb that can be therein accommodated, a master link secured on one end to the center portion of said door, the other end of said master link being connected at two spaced points by two links to two generally similar spaced points on said depending member forming a quadrilateral upper linkage, spacings of the pivot points on said quadrilateral linkage being of such dimension and arranged to cause the center portion of the door to follow the path of the ends ofthe door upon said ends being moved by said power-actuated linkage. Y.

4. Anairplane fuselage having a horizontal transverse partition therein dividing said'fuselage into upper and lower compartments, said lower compartment forming a bomb bay of greater the open position, linkage means secured at' spaced points along said bomb bay to said doors' tol move said doors from a generally horizontal closed position with their inner edges abutting, to la generally verticalvopen position within said bomb bay contiguous the inner walls thereof` to aiord a maximum of clear bomb Ydropping area witha minimum of aerodynamic drag on a bomby run, said linkage means comprising a first rigid link pivoted directly to each door adjacent ,the

central portion of the end thereof and a second rigidlink pivoted directly to each door adjacent the inner edge thereof, said links being directly pivoted to said fuselage at vertically spaced 1o' cations generally above the central portion of the end of the associateddoors when the doors are in closed position whereby upon initial swinging fof` said linksfrom their doorf-closedgp'ositions relative 'to the fuselage, said second links will cause said doors to rock about their pivotal connection with the rst links whereby .to ycause the outer edges of the doors to swingupwardlyy and inwardly of said fuselage to clear the Wall there.- of, and means for so swinging saidlinks. v

WERNER BUCHAL. vCONRAD H. COOKE.

REFERENCES CITED v y The following references are of record Yin the iileof this patent: y

UNITED STATES PATENTS Number Name Date 'f 2,309,686 Winters Feb. 20, -1943 2,338,030 `Edgemond Dec. 28, 1943 2,370,307 Hall Feb. 27, 1945 2,412,729 Hall Dec. 17, 1946 2,457,625 Amiot Dec. 28, 1948 FOREIGN PATENTS Number Country Date 861,598 n France Nov. 4, 194 603,203 Great Britain June 10, 1948 

